1. Field of the Invention
The present invention relates in general to dictation transcription systems, and relates in particular to the art of remotely controlling, and receiving recorded dictation signals from, a preselected one of a plurality of dictation recorders containing recorded dictation.
2. Background of the Invention
Modern dictation systems have become increasingly complex in order to promote convenience and ease of dictation and transcription of the recorded dictation. Remote transcription of recorded dictation efficiently and conveniently is a problem which has seldom been addressed in the prior art. Devices for the remote control of dictation recorders, however, are known in the art and allow dictation to a dictation recorder which is located a distance from an operator. The patent to Fish, et al., U.S. Pat. No. 4,122,305, discloses a dictation machine control unit connected to a telephone transmission line and adapted to respond to signals received over the telephone line for controlling the operating functions of a dictation recorder. The functions of "record", "play back", "review", "stop", "correction mark", "end of letter mark", and "call attendant" are controlled in response to dual tone signals or dial pulse signals generated by a standard telephone instrument, so that an operator may dictate messages from a remote location.
Some of the same recorder functions controlled by the Fish device are desirable in remote dictation transcription systems. For remote transcription, as opposed to remote dictation, it is preferable to control the playback functions of a selected recorder containing recorded dictation from a remote transcription unit. Most often, foot pedals, rather than a conventional telephone instrument, are provided for functions which require movement of the recording media, such as listen, fast forward, and recall, so that the hands of the operator are free to type. In many conventional systems, the remote transcription unit provides a control signal over the telephone line to the selected recorder to initiate the desired function in response to the actuation of a foot pedal. For example, when the operator depresses a listen foot pedal, the recorder plays back the recorded dictation over the telephone line to the transcriptionist, who can hear the recorded dictation through a speaker, head phones, or the like. The transcriptionist then transcribes the recorded dictation.
In conventional central dictation/transcription systems, transcriber stations are connected by multiwire cables, through a switching network, to the recorder. In this type of environment, increased complexity of control functions may be implemented by either adding additional conductors to the connecting cables, or increasing the complexity of the signals placed on the cable. These alternatives cause no basic problem, other than increased complexity so long as the central system is situated so that the direct wired connections may be maintained.
These restraints have placed a practical limit on the distance that remote transcription stations can be placed from the recorders. In other words, in the prior art, it has been necessary to sacrifice sophistication of the functions controlled from a remote location as the distance from the recorders increases to the point at which a common carrier network, such as the telephone network, is used to connect recorder and transcriber. Thus, the basic problem to be solved by the present invention is that of maintaining the ability to provide all desired transcriber control functions over remote links, in particular telephone lines, when the links are basically audio links and the dictation/transcription system designer has no control over the DC voltages and currents on the link, and the link is characterized by a predetermined bandwidth.
In many conventional remote dictation transcription systems, the actuation of a control foot pedal provides a control signal to the recorder which merely initiates the desired function. When the function is to be terminated, a separate termination signal is generated at the remote transcription unit and transmitted via the telephone line to the dictation recorder which terminates the function upon receipt of the termination signal. In systems of this type, the interruption of communication, or the malfunction of the remote transcription unit, may result in the failure of the selected dictation recorder to receive the command to terminate a function which has been initiated. The dictation recorder thus experiences "run-away" by continuing to provide the selected function until the recording media has reached the limitations of its movement. For example, should the telephone line accidentally be disconnected after the provision of a fast forward control signal, a magnetic tape dictation recorder would continue to fast forward until the end of the tape has been reached. Consequently, it would be difficult for the transcriptionist to later determine the point on the tape at which transcription was interrupted without reviewing a large portion of the tape.
The Fish device described above seeks to prevent run-away by detecting the presence of a dial tone on the telephone line. A disconnect sequence which terminates the on-going function is triggered by the dial tone which appears if the telephone line has been disconnected. However, many telephone central offices do not transmit a dial tone upon the line of a receiving party within a consistent or standard time period. Thus, significant run-away may still occur during the time period between disconnection and the appearance of a dial tone.
Other problems exist in providing a convenient and efficient system for the remote transcription of recorded dictation. Often, an experienced transcriber desires to listen to the recorded dictation at a higher speed than is normally provided during playback. Similarly, a novice transcriptionist often desires for the playback of dictation to be at a slower speed than is normally provided. It is known in the art to provide means for selectably varying the speed of playback in directly connected systems. However, previous remote transcription systems have not had the capability to provide a speed of playback which is remotely selectable over a communications link. The Fish device described above does not teach or disclose any techniques for remotely controlling the speed of playback of recorded dictation.
During the transcription of recorded dictation, often it is also desirable for there to be an overlap in playback between dictation previously transcribed and dictation to be transcribed so that the operator can easily identify the point at which transcription ended. In many prior art devices, when the transcriptionist releases the "listen" foot pedal, a predetermined backspace or "recall" of the recorded dictation is automatically provided so as to allow the overlap in playback. Devices which provide the overlap function in the prior art often employ a circuit which automatically backspaces the tape a predetermined amount based upon the timing of a timing circuit. For example, the patents to Bolick et al., U.S. Pat. Nos. 3,632,893 and 3,758,726 employ capacitor charging circuits to provide the timing function. The Fish device described above also employs such a scheme for providing a fixed amount of backspace. However, different transcriptionists often desire different amounts of recall to suit their temperaments, speed and abilities. It has not been possible to remotely provide a remotely selectable variable amount of backspace in devices employing such capacitor charging timing circuits.